Otoscopes are very well known hand-held medical diagnostic instruments used for examining the ear of a patient. A typical otoscope 20, illustrated in FIG. 1, is defined by an instrument head 22 that is supported by a handle portion 24. The handle portion 24 has an interior that is sized to retain a set of batteries 26 as well as an integrated white light source 28, such as an incandescent bulb, the latter usually being disposed within an upper part of the handle portion 24. The output of the illumination source 28 is coupled to the polished proximal end of a set of optical fibers 32 that upwardly extend from the handle portion 24 and through a necked portion of the instrument 20. The optical fibers 32 are configured to encircle the distal end of an axisymmetric insertion portion 36, the latter being formed at the distal end of the instrument head 22. A hollow disposable speculum tip 40 is releasably attached to the exterior of the axisymmetric insertion portion 36, the speculum tip 40 also being defined by a tapered axisymmetric configuration and having respective proximal and distal tip openings 41, 42. A viewing window 50 is provided at the proximal end 25 of the instrument head 22. The viewing window 50 can include a magnifying optic 54.
In use, the speculum tip 40 (shown in phantom in this view) is releasably attached to the distal axisymmetric insertion portion 36 of the instrument head 24. The speculum tip 40 includes an internal feature (not shown) that engages a circumferential bayonet slot 39 provided on the exterior of the axisymmetric insertion portion 36 wherein the tip 40 is twisted rotationally in a locking direction to secure the speculum tip 40 in place. The shape of the speculum tip 40 permits insertion only to a predetermined depth within the outer ear of a patient (not shown). The contained illumination source 28 is typically activated by a user actuable switch 43 that is provided on the handle portion 24 after the speculum tip 40 has been attached to the otoscope 10 in which a ringlet of white light is provided at the distal opening 38 of the axisymmetric insertion portion 36 for illuminating the target. The amount of illumination for examination can optionally be adjusted using a rheostat (not shown). The outer ear, including the tympanic membrane (not shown), can then be examined for otitis media or other signs of infection that can be seen by the caregiver through the viewing window 50.
In other versions, specific optical systems can be provided within the instrument head, such as those found in otoscopes manufactured and sold by Welch Allyn, Inc. under the tradename of Macroview that permits viewing of the entire tympanic membrane all at once, as discussed in U.S. Pat. No. 8,197,403B1, herein incorporated by reference, whether visually or using an electronic imager.
Still other versions can incorporate other specific illumination systems to direct emitted light from a light source toward the target of interest using various means disposed within the instrument head. For example, some otoscopes may utilize a light pipe or waveguide while other systems may provide illumination of a ringlet of optical fibers or alternatively a circumferential array of small LEDs. Still other systems may provide direct illumination relative to the target of interest.
Recently, it has been discovered that utilization of a low power laser light source can provide enhancements to ear examinations and more specifically enable the detection of fluid behind the tympanic membrane; (i.e., effusion in the middle ear which can be deduced from a reflectance pattern obtained from an emitted laser light that passes through, but does not puncture the tympanic membrane). Providing this additional capability would be extremely advantageous for a caregiver to enable a more comprehensive examination of a patient. For example, it is difficult to reliably discern whether an ear infection is viral or bacterial in nature. This distinction is important in that antibiotics are usually an effective treatment against viral infections, but are wholly ineffective against bacterial infections. Because of the above noted difficulty to discern an identified ear infection, antibiotics are often prescribed as a matter of routine. In the course of this latter discovery, a need has therefore developed in the field to be able to readily incorporate a low power laser light source for use in an otoscopic instrument. There is an equally compelling need to be able to be incorporate or retrofit such a feature in existing otoscopic instruments, if possible.